overlay - Computer Definition

In telecommunications, a deployment in which the new infrastructure parallels that of existing infrastructure. In a passive optical network (PON) deployment, for example, this approach enables the service provider to construct the new system and provide enhanced broadband service to PON subscribers as required, while continuing to serve others subscribing to more basic services from the old cable plant. See also brownfield, greenfield, infrastructure, and PON.

(1) A preprinted, precut form placed over a screen, key or tablet for identification purposes. See keyboard template.

(2) A program segment called into memory when required. When a program is larger than the memory capacity of the machine, parts of the program not in constant use can be set up as overlays. Each overlay called in overwrites the existing overlay in memory. Virtual memory provides for automatic overlays. See virtual memory.

Sentence Examples

Deep, which overlay the huge area of the temple, and exposed to view not only the scanty remains of the latest edifice, built after 350 B.C., but the platform of an earlier temple, now known to be that of the 6th century to which Croesus contributed.

From in front and especially from the right, in the unlifting smoke the guns boomed, and out of the mysterious domain of smoke that overlay the whole space in front, quick hissing cannon balls and slow whistling shells flew unceasingly.

Other Churches make them too, though they overlay and disguise them with appeals to tradition and to the authority of the Church itself or the Fathers.